INFO: task kworker/0:6:14176 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:22056 pid:14176 tgid:14176 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 hub_port_connect drivers/usb/core/hub.c:5429 [inline] hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] port_event drivers/usb/core/hub.c:5831 [inline] hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 2 locks held by getty/5565: #0: ffff8880365b20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:4/5867: 5 locks held by kworker/0:7/5895: #0: ffff88801f2c7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000435fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88802aaa5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff88802aaa5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859 #3: ffff88802ac21510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff88802ac21510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5428 [inline] #3: ffff88802ac21510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #3: ffff88802ac21510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #3: ffff88802ac21510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5913 #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5429 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913 6 locks held by kworker/u8:12/8709: #0: ffff88801c2f3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003037d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010d890 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff88807a2920e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88807a2920e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88807a2920e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff88807a291250 (&devlink->lock_key#30){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff88807a291250 (&devlink->lock_key#30){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff88807a291250 (&devlink->lock_key#30){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff90123728 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff90123728 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2089 1 lock held by syz.0.1596/11976: 2 locks held by kworker/0:5/14050: #0: ffff88801b478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9001e817d18 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 5 locks held by kworker/0:6/14176: #0: ffff88801f2c7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9001e47fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88802ac3c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff88802ac3c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859 #3: ffff88802ac3f510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff88802ac3f510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5428 [inline] #3: ffff88802ac3f510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #3: ffff88802ac3f510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #3: ffff88802ac3f510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5913 #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5429 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #4: ffff88802a3b5568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913 1 lock held by syz.0.2953/17531: #0: ffffffff8e3ca9c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3774 8 locks held by syz-executor/17665: #0: ffff8880367ba420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x240 fs/read_write.c:736 #1: ffff8880363b0888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff88802131e008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f6c6b68 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 #4: ffff8880314bd0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff8880314bd0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8880314bd0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #5: ffff8880314bb250 (&devlink->lock_key#29){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1675 #6: ffffffff90123728 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #7: ffffffff8e3caaf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by syz-executor/17697: #0: ffffffff90123728 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x255/0x4740 drivers/net/tun.c:3038 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 Code: 95 62 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 aa 1d 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007e10 EFLAGS: 000002c6 RAX: 00000000022bdff7 RBX: 0000000000000000 RCX: ffffffff8b6c4419 RDX: 0000000000000000 RSI: ffffffff8dbdf8b9 RDI: ffffffff8bf47de0 RBP: fffffbfff1c12ee8 R08: 0000000000000001 R09: ffffed10170865bd R10: ffff8880b8432deb R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e097740 R14: ffffffff9084f010 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249e4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f33dadeeb68 CR3: 0000000034b1f000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:743 start_kernel+0x3e9/0x4d0 init/main.c:1099 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0xb0/0xc0 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x148